Submersible pump



Jan. 24, 1967 E. MEYER SUBMERSIBLE PUMP 4 Sheets-Sheet l Filed Feb. 18, 1965 6 r M m o .N N 5 R e 0 V5 w r MN .1 r M9 M R E H .Y J

Jan. 24, 1967 E. MEYER 3,299,818

SUBMERS I BLE PUMP Filed Feb. 18, 1965 4 Sheets-Sheet 2 Fig.4 Fig.5

Y nventor- [Rm r [YER Jan. 24, 1967 E. MEYER SUBMERSIBLE PUMP 4 Sheets-Sheet 3 Filed Feb. 18, 1965 n w m M mm m Wr a l r n m r Jan. 24, 1967 Filed Feb. 18, 1965 Fig.9

E. MEYER 3,299,818

Fig .10

Inventor- ERA/Jr YER 19 rroR N575 United States Patent O 5 Claims. 61. 103-53) The invention relates to a submersible pump for pumping liquids or other fluids, and more particularly to a submersible pump of the induction type.

Submersible pumps of this kind either are entirely submersed in the fluid to be pumped, or a part only of the housing is submersed.

With submersible pumps of the general kind above referred to as heretofore known, the intake end of the suction duct is disposed at the bottom of the pump housing or at the side thereof to permit a low draining of the vessel containing the fluid to be pumped. In such an arrangement the location of the intake of the suction duct entails that during pumping the fluid level in the supply vessel may decrease to a level above the top of the housing or even close to the bottom of the housing. Pumps of this kind are not safe for the pumping of inflammable liquids. Heating of the pump housing due to a defect in the electrical components of the pump may ignite the liquid at the surface thereof, or the inflammable gases frequently present in a supply vessel.

It is a broad object of the invention to provide a novel and improved submersible induction pump which eliminates the danger of ignition of the fluid to be pumped or of the gases emanating from the fluid, whereby a pump according to the invention may be safely used for the pumping of all kinds of fluids, including inflammable liquids.

The afore-pointed out object, feature and advantage of the invention and other objects, features and advantages which will be pointed out hereinafter are attained by locating the intake opening of the suction duct of the pump above or at least flush with the top level of the pump housing when the pump is in its operational position. The suction duct may, for instance, be in the form of a duct or pipe extending parallel to the axis of the pump assembly and protruding from the top side of the pump housing.

Another object of the invention is to provide a novel and improved filter arrangement which is effective under all operational conditions. According to the invention the filter is disposed within the pump housing, rather than outside thereof, as is conventional.

The invention further provides for arranging the cylinder-piston assembly of the pump assembly proper so that it can be withdrawn from the housing through the top wall thereof, thereby facilitating servicing or replacing of the pump assembly.

The invention finally provides safety means for automatically preventing the sucking of air into the pump when the fluid in the supply vessel decreases below a predetermined level. Such safety means may comprise a float which automatically opens or closes the suction duct, depending upon the fluid level in the supply vessel.

In the accompanying drawing several preferred embodiments of the invention are shown by way of illustration, and not by way of limitation.

In the drawing:

FIG. 1 is a sectional diagrammatic view of a submersible pump according to the invention;

FIG. 2 is a fragmentary diagrammatic view ofa conventional submersible pump;

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FIG. 3 is a similar fragmentary diagrammatic view of a pump according to the invention;

FIG. 4 is a diagrammatic view of a pump according to the invention placed in a vessel containing a supply of liquid to be pumped;

FIG. 5 is a view similar to FIG. 4, showing the liquid level during a stage of a pumping operation;

FIGS. 6, 7 and 8 diagrammatically show different stages of removing the pump assembly from a pump according .to the invention;

FIG. 9 is a diagrammatic view of a pump according to the invention equipped with safety means for preventing the sucking in of air during a pumping operation;

FIG. 9a shows a safety valve of the pump according to FIG. 9 in detail;

FIG. 10 is a view similar to FIG. 9 but showing a different stage of the pumping operation and the safety means in a different position, and

FIG. 10a shows the safety valve of FIG. 9a in another operational position.

Referring now to the figures in detail, the submersible induction pump as exemplified in FIG. 1 comprises an induction pump assembly BF. The assembly should be visualized as being generally conventional. It includes a spring-loaded cylinder-piston assembly which when reciprocated pumps fluid through a delivery duct F connected thereto. The reciprocatory action is obtained in a conventional manner by sequentially excited induction coils B which are connected by means of conductors L to a source of power and a suitable cycling switch means. The entire pump assembly may be encased in hardened insulation material C encapsulated by a closed housing D. The liquid or other fluid to be pumped is sucked in through a suction duct E, which protrudes from the top cover of the housing, the top side of the housing in the operational position of the pump being at the right end of the housing, as shown in FIG. 1. Suction duct or pipe E preferably extends parallel to the center axis of delivery duct F and thus of the entire pump assembly.

Turning now to FIG. 4, this figure shows the pump of FIG. 1 fully submersed in liquid contained in a vessel H. The pump is shown in its upright operational position. The liquid level is indicated by G. FIG. 4 shows the decrease of the level due to a pumping action. As is evident, the liquid level G cannot decrease below the intake mouth of suction duct E. Accordingly, the pump housing will always be fully submersed in the liquid.

Liquids to be pumped frequently contain dirt particles and similar impurities. The pumping of such impurities may damage or clog the pump assembly or valves in communication with delivery duct F. It is customary to provide filters in front of the intake mouth of the suction duct and to locate such filters below the pump housing, or as is shown in FIG. 2 for filter A, laterally thereof. As was pointed out before, with pumps as heretofore known the liquid level may be lowered so far that a substantial part of the pump housing is exposed, which also may result in at least a partial exposure of the filter. Such exposure reduces the efliciency of the filter correspondingly and is another reason why it is not considered safe to use submersible pumps with filters disposed either laterally or below the pump housing for pumping inflammable liquids.

According to FIG. 3 the filter is mounted on the up-v wardly protruding portion of suction duct E. (The operational position of the housing according to FIG. 3 is the position turned through in counterclockwise direction.) Such an arrangement is better than the one shown in FIG. 2, but is still not fully satisfactory, since the liquid level may sink to the level shown in FIG. 5, in which the filter would be partly exposed.

According to FIG. 1 the filter A is disposed within the pump housing and preferably closely adjacent to the intake side of the pump assembly. In such an arrangement the liquid must always be sucked through the entire filter before entering the pump assembly, irrespective of the level of the liquid in the supply vessel.

To clean filter A, as is necessary from time to time, the bottom of housing D (which is on the left side of FIG. 1) may be removed. However, cleaning of the filter by removing the bottom of the housing entails the danger that, due to inadvertence, the pump may be re-started without attaching the bottom. In such event the protective effect of the upwardly protruding suction duct B would be lost, since liquid would be sucked in directly through the bottom, and as a result the pump according to the invention would become unsafe for pumping inflammable liquids.

According to the invention the interior of the pump housing is not. accessible through the side wall or the bottom wall of the housing, but is accessible only through the top wall. As is shown in FIGS. 6, 7 and 8 in three stages, the pump assembly is removed through the top wall. The top wall is arranged so that it permits withdrawal not only of the cylinder-piston assembly proper, but also of the filter. The shape and material of the filter A should of course be such that it can be withdrawn through the topwall of the housing, together with the cylinder-piston assembly. The induction coils B remain within the housing when the cylinder-piston assembly and the filter are withdrawn.

FIG. 7 shows the cylinder-piston assembly partly withdrawn, and FIG. 8 shows a complete withdrawal of the assembly.

Turning now to FIGS. 9, 9a and 10, 10a, as is evident from these figures, a decrease of the liquid level G to its minimum levelthat is, to a level flush with the intake end of suction duct Ewill result in the sucking in of air. The sucked-in air will fill the free space in the pump housing and eventually may invade the delivery duct or pipe. Accordingly, the delivery of liquid will cease. It may occur that the sucked-in air cannot escape either through the pressure duct or the suction duct of the pump, in which event it will form an air block in the system, so that the pump will not suck in liquid even when the liquid level in the supply vessel rises above the minimum level shown in .FIG. 10.

To prevent such blocking, the invention provides safety means precluding the formation of an air block. These safety means are indicated in FIGS. 9 and 10 by a dotted circle labeled X, and are shown in detail in FIGS. 9a and 10a. As is shown, a safety valve comprising a float K, such as a hollow ball, is provided above the intake mouth of suction duct E and retained by a cage M. The float will sink gradually from the position of FIG. 9a as the level G decreases and will finally seat itself upon the mouth of duct E,.thereby closing the same, as is shown in FIG. 10a.

As is evident, the float acts in the manner of a one-way valve and eifectively prevents the sucking in of air when the level G is as low as is indicated in FIG. 10a. When the liquid level rises, ball K, due to its buoyancy, will also rise in its cage M, thereby assuring that the pump will immediately reassume operation without requiring a preceding pumping of air from the pump housing or the pipe system connected therewith. Cage M should be visualized as being perforated or made of a netting mate! rial, as is indicated by dotted lines.

The float K may of course be disposed at any desired distance from suction duct E. It may be arranged above the suction pump, or at the side thereof. The movements of the float are then utilized to operate a cover for suction duct E by suitable transmission means, such as a linkage, a chain, etc.

While the invention has been described in detail with respect to certain now preferred examples and embodiments of the invention, it Will be understood by those skilled in the art, a-fter understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended, therefore, to cover all such changes and modifications in the appended claims.

What is claimed is:

1. A submersible pump for pumping liquid from a supply of liquid, said pump comprising an operationally upright closed housing, an induction-operated suction pump assembly mounted in said housing, an intake duct for sucking liquid to be pumped into the pump housing, said intake duct having an outlet opening within said housing and an upright portion outwardly protruding at the top side of the housing and terminating in an inlet mouth for the liquid, a filter for filtering out sucked-in impurities, said filter being disposed within said housing in front of and adjacent to the outlet opening of the intake duct, an outlet duct for discharging pumped liquid fromthe housing, and a safety valve means at the inlet mouth of the intake duct to close said mouth when the level of the liquid to be pumped decreases below a predetermined level.

2. A submersible pump according to claim 1 wherein said intake duct is in the form of a pipe extending within the housing parallel to the longitudinal axis of said pump assembly.

3. A submersible pump according to claim 1 wherein the top side of said housing includes an opening, and wherein said pump assembly comprises induction coil means mounted within the housing and a cylinder-piston assembly, said outlet duct protruding through said opening in the top side of the housing and being secured to said cylinder-piston assembly to form a structural unit therewith withdrawable as a unit through said opening.

4. A submersible pump according to claim 1 wherein said safety valve means comprises a float valve at the inlet mouth of said intake duct for closingsaid inlet mouth when the level of the liquid to be pumped decreases below said predetermined level. i

5. A submersible pump according to claim 4 wherein said valve comprises a float and a cage confining said float movable between a position covering the inlet mouth of said intake duct and a position uncovering" said inlet mouth, the position of the float being controlled by the level of the liquid to be pumped.

References Cited by the Examiner UNITED STATES PATENTS 583,736 6/1897 Eppich 137-433 2,961,149 11/1960 Hull 230-55 3,181,194 5/1965 Daykin et a1 103--53 X FOREIGN PATENTS 736,101 8/1955 Great Britain.

ROBERT M. WALKER, Primary Examiner. 

1. A SUBMERSIBLE PUMP FOR PUMPING LIQUID FROM A SUPPLY OF LIQUID, SAID PUMP COMPRISING AN OPERATIONALLY UPRIGHT CLOSED HOUSING, AN INDUCTION-OPERATED SUCTION PUMP ASSEMBLY MOUNTED IN SAID HOUSING, AN INTAKE DUCT FOR SUCKING LIQUID TO BE PUMPED INTO THE PUMP HOUSING, SAID INTAKE DUCT HAVING AN OUTLET OPENING WITHIN SAID HOUSING AND AN UPRIGHT PORTION OUTWARDLY PROTRUDING AT THE TOP SIDE OF THE HOUSING AND TERMINATING IN AN INLET MOUTH FOR THE LIQUID, A FILTER FOR FILTERING OUT SUCKED-IN IMPURITIES, SAID FILTER BEING DISPOSED WITHIN SAID HOUSING IN FRONT OF AND ADJACENT TO THE OUTLET OPENING OF THE INTAKE DUCT, AN OUTLET DUCT FOR DISCHARGING PUMPED LIQUID FROM THE HOUSING, AND A SAFETY VALVE MEANS AT THE INLET MOUTH OF THE INTAKE DUCT TO CLOSE SAID MOUTH WHEN THE LEVEL OF THE LIQUID TO BE PUMPED DECREASES BELOW A PREDETERMINED LEVEL. 